Dark Blue
by Memekri Vantass
Summary: This takes place in the post-pacifist run in the UnderSwap. Sans started to act strange when he left the underground. He seems like he's hiding a few things... And something about himself... Something dark. Read the story to find out what they are! Warning: This story will have dark content. Be prepared for feels. Also... Maybe Swapcest... Not really sure if I will or not.
1. The Beginning

It was late and it was the first night at the monsters were freed from the underground, thanks to Chara. Papyrus and Sans were sitting at the top of the mountain, watching the night sky in awe. After so many resets… So many deaths… It was such a change to actually be outside Mt. Ebott. Papyrus was happy and finally felt relaxed, but noticed something about Sans... As soon as Sans was outside Mt. Ebott, he had a look of worry… He kept glancing at Chara, almost expecting something… But when he asked, Sans gave him the strangest answer.

-Flashback-

"Hey, Bro. What's up? You seem a bit tense." Papyrus asked, making Sans jumped a bit. He then looked up at Papyrus with his signature smile. "It's nothing important, Papy~!" Sans smile fell a bit, eyes lights disappearing for a moment and mumbled. "... at least i hope it's not…" His eye lights reappear and his smile is full and cheery again. "Whelp! I'm off to greet the humans!" And with that he ran off toward the nearby town.

-Back to the Present-

Papyrus looked at Sans, noticing he was in deep thought. Papyrus nugged Sans to get his attention, causing Sans to jump again and looked at Papyrus. "Bro, you seem to be in some deep thinking there. Mind telling me what you're thinking?" He was worried about Sans. Sans was never like this… Ever. Sans frowned and looked at the sky. "Just stuff… Nothing important, Papy." Papyrus frowned and sighed, looking back at the night sky. "Okay… But if you need to talk about anything. I'm here to listen." Sans had a sad expression, but quickly hid it with his cheer. "I know, Papyrus."


	2. Changes

-Papyrus POV-

Everything was actually really nice. Chara has been going to Asgore's new school along with every other monster kid. Chara's still the only human going to the school at the moment, but over time, other human children she start attending. Asgore is happy to have the school, he keeps telling me about all the nice children and how they silly they can be. Undyne is working on joining the human scientist and Alphys is trying to become a cop. Oh, and they are dating now. Thank Toriel, it was awkward for the longest time with those two. Queen Toriel, or well… Toriel, is working on the campus of the school, from being grounds-keeping to being a substitute teacher when needed.

And Sans and I? Well, I'm haven't really changed all that much, besides being happier and less lazy. I'm actually doing some productive stuff, like getting a job at Muffet's new diner. The place can get really busy, but I don't really mind. It's fun to interact with the usual patron and the new ones as well. And Sans… Oh boy. How do I even start talking about him? Well, after he left the mountain, he looks like something's bothering him. And usually, he tells me what's up with him so I can help him out, but… He's been keeping a distance from me and everyone else. And at time, when I have trouble sleeping, I go to check on him and he's not in his bed. So I go to look for him and he's always looking at the stars… Mumbling. Like he's talking to someone. I see him cry sometimes as well. I usually walk over to him to try and comfort him, but he… glares at me, tells me to leave him alone, and walks back inside and to his room. Sans was never like this before and it's starting to really worry me. He was never like this in any of the resets. I talked to Chara and they said the same, and this caused them to worry as well. I don't know what I can do to help him, but I think I'm going to try and force him to talk. I hate doing it, but I've tried waiting for him and he just keeps pushing me away more and more. I will try tomorrow, after work. He doesn't really leave the house unless it's night or Alphys forced him to go out. I hope everything is okay with him…


	3. Weirdness

-Papyrus's POV-

I get home after a long day at work. Now usually when I get home, I take an hour long nap then I make dinner, since Sans stopped doing that. I mean, I not complaining, I do like making pasta related meals more than tacos. Though, unlike Sans, I get store branded everything, because I don't have the energy to make everything myself. I may not be as lazy, but I still am lazy. The point is, I'm not taking an hour long nap! I'm going to have an hour long talk with Sans in hope to figure out what's up with him.

I walk to his room door, which looks… Unpleasant… It has a lot of "No Entering" Signs, and even a "No Little Brothers Allowed" Sign. Wow… I can feel his such _caring love_ for me from here… I knock on the door. "Sans?" I called out, hoping to get a response from him. Nothing. I knock a bit louder. "Sans!" I called out. I heard the shuffling of his blankets. Was he… Sleeping? The door opened, showing both him and his messy room. Why it was so messy, made no sense, since Sans always yelled at me to pick up my stuff.

"What the hell do you want?" He grumbled out. He sounded so tired and worn out. "Well, I just wanted to talk to you, you haven't really been acting like yourself and it's worrying me." I hoped he'd talk. He glared and just turned away. "Fuck off." And with that, the door was slammed in my face. What… Just happened. That was weird. And to name the few weird things. One, he cussed. Two, he looked so tired. Three, he's rude as fuck. And four, his eyes weren't the nice sky blue that I'm so used to. They were a darker blue. They looked like all life was lost in them. Like there was nothing to live for… What could have caused this?

I knocked on the door again in hopes Sans would answer. "Sans! Please, I just wanna talk!" Nothing. Time to use a little force. I went to open the door and as soon as I was I heard the click of the doorknob turning, I heard something else. After a moment of trying to figure it out I realized what it was and back away quickly. Milliseconds later, I watched a bone come out of the door and get stuck. I sighed in relief, glad I realized what was going on before it was too late. "Sans! That could have killed me!" I yelled, annoyed at his actions. "Yeah, I know… But are you dead? No. Now leave me alone." I groaned in annoyance. This was going to be a lot harder than I thought. I gave up for now and went to the couch. Guess I get a nap after all… I look at Sans' door one last time. The bone dissipated and there as a hole in the door. Know Sans, he'll probably fix it… I shut my eye sockets and take a nap.


	4. Who?

Heya! I'm so sorry for that! I've been rather uninspired, so I wasn't really writing anything… But after listening to a few songs, I finally got some ideas and now I'm writing again~! The next chapter will be short, but at least I'm continuing~

Welp~ Enjoy!

* * *

-Papyrus' POV-

It's been a week since he actually attacked. He hasn't come out of his room since then, and I keep trying to talk to him but it just doesn't seem to want to. I wish I could do something for him, I wish I can help him, but how can I help him if I can't even get to him. I should probably ask the others for help, but would they even be able to help? I can't talk to him, so how would they be able to get to him? Maybe I just have to wait. Maybe eventually he'll want to talk to me. Maybe.

-Sans' POV-

I lay in bed staring at the ceiling. It's been awhile since we've gotten to the surface. Everyone's been happy; Papyrus, Undyne, Alphys, Chara, Queen Toriel, Asgore. All of them. But for some reason I haven't been able to be happy... Who am I kidding, I know exactly why I'm not happy and I wish I didn't know. I wish I can just be happy like the others. To be like the me in the Underground. To be able to be cheerful and happy. But that's just a wish that will never come true. It be nice to be able to forget... And it be nice for him to not exist.


	5. Reset?

It's had just passed Halloween, all the monster on have actually found it really fun! Humans actually didn't mind monsters at all that night. All monster were happy to be able to celebrate such a fun holiday with the humans. Some of the humans had really amazing costumes as well! But… One monster didn't have fun… He will admit, it was pretty fun to dress up and go out that night… But he doesn't care for it. He was fine with staying in his room.

-Sans' POV-

Chara was invited to spend the night. Papyrus said it would be good for me to spend some time with our friends again, since I don't do that some much. Chara and Papyrus were in the living room while I made dinner. What's for dinner? Obviously tacos. I stare blankly at the finnish food and frown. I was tired of this… I'm tired of this timeline. And Chara doesn't look like they are going to reset anytime soon. So I guess it's time for me to speed that up. I grab a secret ingredient and put it in Chara's taco. It wasn't noticeable, so no one will know anything.

I grab the tacos and put on a cheerful smile, bringing the tacos into the living room and gave Papyrus and Chara the tacos. They smiled and started to eat. "These are delicious, bro." He smiled a bit more. I was happy Papyrus thought it was good. I looked at Chara. "Do you like it~?" I ask with a cheer. Chara nodded, giving me a thumbs up. They continued to eat and I smiled more and went back to the kitchen and grabbed my plate of tacos and went back in, sitting next to Papyrus and chatting with them as I ate. It was a boring chat… Just how school was going for Chara and a bit about Papyrus's job.

A hour or two later, it was time for bed. Chara was already was asleep thanks to what I put in their taco. Papyrus said he was going to bed and went to his room. I stayed with Chara, waiting.

Waiting.

Annnnd it's time!

I picked up Chara and closed my eyes for a moment. The next, I opened them and we are far from the house. I was tired though… I was never able to get used to teleporting. With such a high magic reserve I never understood why it takes so much out of me. Papyrus is able to do it like it's nothing. I set Chara down and moved away from them. I summon many sharp bones over Chara.

Now… It's time for this timeline to end!

I smiled darkly and the bones all stab Chara. I watched their soul float up and finally. It shattered. I chuckled darkly, my eyes glowing a dark blue.

… _I'm so very sorry, Chara._

 **[TRUE RESET]**


	6. Regret and Differences

-Sans' POV-

He jolted awake and was panting, tears running down his cheeks… He stared at his hands… It took him a moment to calm down, but once he did, he looked around… No. Nononono! It has to be a dream! This has to be a dream! He didn't do that! He didn't! Wake up, wake up, wake up! He was pinching his bones trying to wake up from this. But it was all too real. More tears fall. He killed Chara… He killed them so they can reset! He sobs for a while, unable to handle all this. Thankfully, he was slowly forgetting, figuring out it was a True Reset and not a normal one... But before he could forget everything, he grabbed a notebook and wrote down everything that had happened in the last reset. He then grabbed a sketchbook and drew down the last thing he saw… The dark room… Bones sticking out of Chara… A red soul shattering. His eyes flash dark blue for a second and he holds his head… "... You're awful for doing this…" He muttered before putting the sketch book away.

-Papyrus' POV-

I wake up, quite happy for the day. Why wouldn't he be happy? He was on th-

…

Wait a moment.

He looked around his room and his good mood crashed into the fucking mountain. He was in his room… His old room. The one in Snowdin. Why? WHY?! Chara fucking promised him that was the last reset! They promised! He grumbled. He trusted the kid for one moment and this is what he gets?! He gets up angrily and walks downstairs. Sans should be making breakfast by now. Being his happy cheery self. He walked into the kitchen to see he wasn't there. He cocked his eye. Was Sans still asleep? He was about to go check on Sans till he saw him enter the kitchen.

"Morning Papy~" Sans said cheerfully.

"Morning…" Sans didn't say 'Good morning' He always said that till they were on the surface… He stopped after that because… Well… He guess it was because Sans didn't have good mornings, which was still strange. "How are you this morning?" He asked casually. Sans usually told him the truth.

"I am quiet excellent this fine morning~ Though, I am rather upset I overslept just a bit. That is an awful habit to start doing! I'll have to stop that right away! I don't want to end up being like a lazybones like you!" He pouted adorably.

"Yeah, don't need that, bro." He smiles, glad it was just him upset he overslept. "So, what's for breakfast?" I ask, knowing exactly what he's going to cook.

Sans took a moment to answer, before saying, "Anything? I don't really feel like cooking at the moment." Okay… That wasn't an answer he expected… Like… At all. Sans loves cooking. The only time he didn't cook was… Did the last reset actually affect his brother? "But that just means I'll have to make a nice big lunch later~ Mwahahahaha~!" Well… That's more settling, but he's still worried.

"Sans… Are you okay? You never not cook. Did something happen yesterday?" He couldn't help but ask.

Sans noticeably flinched… What was wrong? Did something act- "No, I'm just a bit more tired. Alphys' training can be quite exhausting sometimes. It's nothing to worry about, Papy~!" It seems like he's telling the truth… Sans was a horrible liar and he could easily see through Sans' lies.

"If you say so." He sighs. "I know you hate taking breaks, but you should take one every once in awhile. If you don't, you could possibly hurt yourself."

Sans smiled more. "I will. But only once in a great while! For I do not want to become lazy!" He did his usual laugh. "Now, it's almost time for work! Eat whatever you plan to eat and we shall get going!" He grabbed a bowl, a box of cereal, and the milk and he made himself a bowl of cereal.

I grab myself a bowl and made the same thing. We sat in silence as we ate… Usually Sans talked about anything and everything. Why was he so silent? Something must have happened to him, but what? Why isn't he talking? Why… Why did his eyes show stress and regret? He never seen them like that. Something bad happened to him. Whatever happened… Sans doesn't seem to want to talk about it. He decides to not ask and finishes his cereal.


End file.
